Corn standing in water or in saturated soils causes concern that yields will be affected once the field dries out and the plants start growing. But according to University of Illinois Extension agronomist Emerson Nafziger, reduced yields may not occur. He says corn is a tropical plant and does well at withstanding many stresses common during a growing season.

“There are always concerns about how poor growing conditions or stress during early vegetative growth — V5 to V8 or so — might result in permanent damage to yield potential,” he says. “This concern arises from the knowledge that the ear starts to develop during this period, and the assumption that full potential can only be reached when conditions are ideal. While we would rather have the crop experience no stress during the entire season, there is little evidence to suggest that yields are often curtailed by what happens during vegetative growth.”

Nafziger says observations and some experiments suggest that as long as the height and leaf area of the crop aren’t compromised, crops that undergo some stress during early to mid vegetative growth can yield very well.

“In part, the resistance of corn to stress during mid vegetative growth or earlier to mild or moderate stress is related to counterbalancing, positive effects that accompany the stress,” he explains. For example, dry June weather usually comes with a lot of sunshine, so daily photosynthetic rates may be high even though leaves curl some in late afternoon. High temperatures help speed crop development, even though they tend to favor top growth over root growth.

“Much of the stress tolerance of young corn plants stems from the fact that it’s a crop of tropical origin,” he adds. “Corn is physiologically resilient and not easily damaged by the ups and downs of a typical growing season.”

For more information about what the crops need now, read the June 17 edition of The Bulletin.